Dillard took several pregnancy tests that came back negative, but got a plus sign when she took one of the tests her mother keeps at home, according to People, which first reported the news. "About 30 days after Jill and Derick got married, they gathered everyone in the living room and shared the news," Dillard's father Jim Bob told People. "We were in shock too."

The new season of 19 Kids and Counting, which will feature Jill and Derick's wedding and plans for parenthood, premieres Tuesday, Sept. 2 at 9/8c on TLC.